Grinding and polishing apparatus



Nov. 24, 1.936. c. HAWES GRINDING AND POLISHING APPARATUS Filed Dec. 22, 1 953 INVENTOR. Q ar/fc' f/aa/eo Patented Nov. 24, 1.933%

2,061,626 GRINDING AND POLISHING APPARATUS Charlie L. Hawes, Ashtabula, Ohio Application December 22, 1933, Serial No. 703,563

7 Claims.

In the mounting of grinding and polishing wheels, there has been no particular difficulty with devices for rough or ordinary usages. In the case of precision work however, if a bodily-movable wheel is desired, it has been a serious problem to attain free mobility and yet have sufficient accuracy. Vibration and chattering and rebound have constituted difficult obstacles. A constructicn which offers freedom from such limitations, and which is at the same time not unduly complicated, is accordingly an important desideratum in the art.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:-

Figs. 1 and 2 are a side elevation and a rear elevation, respectively, of an embodiment of the invention; and Fig. 3 is a rear elevation of a modification.

Referring more particularly to the drawing, there is shown a shaft 2 for a grinding or polishing wheel this shaft being mounted in a crosshead l which is in general vertical orientation, carrying the grinding or polishing wheel above a work-support 5 which may be of simple or more or less elaborate detail as desired, and involving a stationary or traveling support according to preference, the detail of this however being immaterial. The cross-head l is freely vertically movable, and ismaintained in parallelism irrespective of variations up or down in its position, and one means of accomplishing this may comprise a plurality of rock-arms 6, l, pivoted to the frame 8 at one end 9 of the arms respectively, and pivoted to the cross-head 4 at the ends I0 of said rockarms, such that the entire cross-head 4 carrying the shaft 2 and wheel 3 may have movement up and down, as desired, While tethered however, to the frame by the rock-arms. Parallelism of the cross-head in a vertical plane is thus maintained irrespective of the particular height at which it may be positioned with respect to the work-support 5. A screw-threaded control I I may be applied for the regulation of the crosshead with respect to the frame 8 and work-holder 5, as for instance by a hand-wheel and nut l2 bearing upon the top of the frame. While the shaft 2 may be driven by a motor carried thereon,

generally I prefer to carry the weight of the motor at a lower point with respect to the cross-head, and by this means it becomes possible to introduce an additional stabilizing factor. For instance, the motor M may have its bracket mounting directly attached to the cross-head at its lower portion, and a suitable belt connection I) may then serve to drive the shaft 2. If the points of pivoting 9, l, for the arms 5, l, carrying the crosshead are provided with suitable bearings or mountings, the entire cross-head with its components and supported parts may be carried with a particularly accurate responsiveness and freedom of balance.

As an equalizing support means for the crosshead and wheel assembly carried thereby, a responsive counter-means is applied. Depending upon the precise character of work to be operated upon, this may take slightly different forms. As

shown in Fig. 2, a counterweight l3 may be con- H nectecl to the crosshead 4 by cables I l running over sheaves l5. This is sufiiciently responsive for work of general character in which no great precision is required. As a further refinement however, it is advantageous to apply a fluidmeans for this. A fluid-pressure plunger l6, advantageously of a form comprising a movable cylinder slidable over a fixed piston, may be arranged at a point below to take against a suitable projection ii on the cross-head. Thus, when in a position as illustrated by the dotted lines in Fig. 2, such fluid-pressure head may support the crosshead with a predetermined pressure-value, as for instance by carrying the main air-supply tank at a desired pressure-figure. With such cushioning support of the cross-head and working elements carried thereby, the movable mechanism is stabilized in a manner effective and simple. An additional air-cylinder l8 may be provided if desired, and having its air-line supply 118a. independent of the air-line Ilia of cylinder I6.

In some instances, a preferable arrangement is a fluid-pressure head in the form of a bellows 20, Fig. 3, mounted on a bracket 2! carried by the frame 8, and having a line 22 for the pressure fluid, for instance air. The upper end of the bellows 2!! thence forms a support upon which a bracket or shaft-housing of the cross-head l may rest. By maintaining a predetermined de sired pressure in the supply system 22, etc., the cross-head i and mechanism carried thereby is stabilized with great precision, with elimination of chattering and bounding and attendant difliculties.

Additional weights 23 may be availed of, for

instance by positioning on a support bar 23a on the cross-head, and addition or subtraction may be made in accordance with pressure desired on any particular piece of work being ground or polished.

By making the frame 8 of wrought metal or steel, as opposed to castings, a particularly low vibrational response is attained, a matter which is found to be of marked importance in high speed work. To the extent desired also, the frame plate may be shaped around into a more or less complete closure 24, and the mechanism be housed in except for the necessary exposure of the grinding or polishing wheels 3. A suitable cut-out or slot 25 may then allow movement of the projecting wheel-shaft 2. The frame 8 may thus be primarily of large channel or U-section, and the enclosure completed as desired. Where frame joints or seams occur these may be welded.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the means stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A grinding and polishing machine, comprising a frcme, a grinding or polishing wheel, a shaft for the grinding or polishing wheel, a crosshead for carrying said shaft, a screw-threaded control means in said frame for positioning said cross-head with total freedom of upward movement, means for mounting said cross-head in maintained parallelism in said frame, and means for fioatably supporting said cross-head without connection thereto.

2. A grinding and polishing machine, comprising a frame, a grinding or polishing wheel, a shaft for the grinding or polishing wheel, a cross-head for carrying said shaft, and a fluidpressure bellows unconnected to said cross-head supporting and cushioning the same.

3. A grinding and polishing machine, comprising a grinding or polishing wheel, a shaft for the grinding or polishing wheel, a cross-head carrying said shaft, a screw-threaded control means in said frame for positioning said cross-head,

fluid-pressure means unconnected to said crosshead cushionably supporting the same, and housing-means enclosing the said frame and crosshead.

4. A grinding and polishing machine, comprising a grinding or polishing wheel, a shaft for the grinding or polishing wheel, a cross-head for carrying said shaft, and means for inhibiting vibration of said wheel, said means including a wrought metal frame, rock-arms connecting the upper and lower portions of said cross-head to the frame, a driving motor secured to said cross-head below said shaft, and means for cushionably supporting said cross-head.

5. A grinding and polishing machine, comprising a grinding or polishing wheel, a shaft for said wheel, a cross-head in which said shaft is carried, means for mounting said cross-head for freedom of movement in a vertical plane, and means for inhibiting vertical vibration of said wheel, said means including a frame of low vibrational-response, a driving motor hung on said cross-head below said shaft, and a cushion in the path of said cross-head.

6. A grinding and polishing machine, comprising a grinding or polishing wheel, a shaft for said wheel, a cross-head in which said shaft is carried, means for mounting said cross-head for freedom of movement in a vertical plane, and means for inhibiting vertical vibration of said wheel, said means including a frame of low vibrational-response, a driving motor hung on said cross-head below said shaft, and a fluid-pressure buifer in the path of said cross-head opposing downward movement thereof.

7. A grinding and polishing machine, comprising a grinding or polishing wheel, a shaft for said wheel, a cross-head in which said shaft is carried, means for mounting said cross-head for freedom of movement in a vertical plane, and means for inhibiting vertical vibration of said whee-1, said means including a frame of low vibrationalresponse, a driving motor hung on said crosshead below said shaft, and a fluid-pressure bellows supporting said cross-head against vibration.

CHARLIE L. HAWES. 

